Metaplastic Variant of Invasive Micropapillary Breast Carcinoma: A Unique Triple Negative Phenotype
ABSTRACT Invasive micropapillary carcinomas (IMC) and metaplastic breast carcinoma (MBC) have different clinicopathologic features. This study reports an unusual case of multifocal grade III IMC associated with MBC component in a 35-year-old woman. MBC was vimentin positive, pancytokeratin negative, and showed focal p63 positivity. Immunostains for estrogen and progesterone receptor, and fluorescence in situ hybridization for Her2/neu amplification were negative. All the left axillary lymph nodes dissected were positive for metastatic carcinoma with ductal and IMC patterns, but without metaplastic component. Postmastectomy computed tomography and magnetic resonance imaging scans showed metastases to lungs, liver, brain, and vertebrae. The biologic behavior of tumor was in accordance with histology, so that the nodal and distant metastases were testament to the underlying inherently aggressive IMC, whereas large tumor size and triple negativity reflected the features of MBC. To the best of the authors' knowledge, this is the first report of a metaplastic variant of invasive micropapillary breast carcinoma with triple negative phenotype.
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ABSTRACT: Invasive micropapillary carcinoma (IMPC) is a rare subtype of epithelial tumor of the breast listed in the 2003 World Health Organization histologic classification of tumors of the breast. It is characterized by inside-out micropapillary morphology, frequent lymph vessel invasion (LVI), and lymph node metastasis; however, its etiology remains unknown. This study investigated the incomplete inside-out growth pattern (IGP) in invasive ductal carcinoma, not otherwise specified (NOS), and examined the association between incomplete IGP and clinicopathologic features, including the presence of intratumoral lymph vessels (ILV), LVI, nodal metastasis, and prognosis. Tumor tissues from 166 invasive duct carcinomas NOS and 10 IMPCs were immunostained using an anti-epithelial membrane antigen antibody to detect IGP and with D2-40 antibody to determine the presence of ILV and LVI. Incomplete IGP was detected focally in 88 (53%) of 166 invasive duct carcinomas NOS. Transition areas between IMPC and invasive duct carcinoma NOS also showed prominent incomplete IGP in 9 (90%) of 10 IMPCs. Incomplete IGP in invasive duct carcinomas NOS was associated with larger tumor size, higher frequencies of ILV, LVI, nodal metastasis, and poorer recurrence-free survival by univariate analysis. Incomplete IGP, ILV, and tumor size independently affected LVI by multivariate analysis. These findings indicate that incomplete IGP of tumor cell clusters is not uncommon and is a useful tool for predicting LVI in invasive duct carcinoma NOS of the breast.Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 02/2011; 458(2):159-69. DOI:10.1007/s00428-010-1033-2 · 2.56 Impact Factor
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ABSTRACT: Invasive micropapillary carcinoma of the breast is a distinct variant of breast cancer. In the present study, we analyzed potential immunophenotypic changes in invasive micropapillary carcinoma. Specimens from 15 patients with invasive micropapillary carcinoma were analyzed using clinicopathological and immunohistochemical methods. We also examined the relationship between clinicopathological factors using the Ki-67 labeling index. Immunohistochemical staining for cytoplasmic p63 expression was seen in four (27%) tumors, and p63 nuclear expression was also observed in four (27%) tumors. Involucrin and 34betaE12 were expressed in the invasive micropapillary carcinoma component of nine (60%) and four (27%) tumors, respectively. Cytokeratin 5/6 was expressed in three (20%) tumors and cytokeratin 14 staining was negative in all tumors. In one tumor (case 3), vimentin, epithelial membrane antigen and cytokeratin 8/18 were co-expressed. Four tumors (27%) were negative for the estrogen receptor/progesterone receptor/HER2. However, 11 out of 15 (73%) tumors were positive for the estrogen receptor. The Ki-67 labeling index was significantly higher in cases with p63 tumor expression than in those without (P < 0.0001), and also higher in cases with lymph node metastasis than in cases without (P = 0.0029). Nuclear expression of p63, involucrin and 34betaE12 were detected indicating squamous differentiation. Cytoplasmic p63 expression was also identified. The fact that the Ki-67 labeling index was significantly higher in such cases may have been associated with the aggressive behavior of these tumors. Our findings suggest that the characteristic morphology of invasive micropapillary carcinomas may be due to immunophenotypical and oncogenic changes.Japanese Journal of Clinical Oncology 05/2010; 40(8):781-7. DOI:10.1093/jjco/hyq056 · 1.75 Impact Factor
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ABSTRACT: Invasive micropapillary carcinoma of the breast is an aggressive and distinctive variant of breast cancer. These tumours have a characteristic histological appearance and have been associated with a high incidence of axillary lymph node metastases and a poor clinical outcome. The aims of this study were to investigate the immunohistochemical profile of invasive micropapillary carcinoma of the breast, to compare it with invasive ductal carcinoma, and to identify the morphological parameters which predict its poor outcome. Fifty-three (2.6%) invasive micropapillary carcinomas of the breast from 2022 cases of infiltrating breast carcinomas were identified by retrospective review. The patient age at presentation ranged from 33 to 78 years (mean 52.5 years). The tumour size ranged from 5 to 70 mm (mean 27 mm). Eighty-two percent (43 of 53) were of high histological grade; 69% (33 of 48) of cases with axillary lymph node dissections had positive lymph nodes; and 75.5% (40 of 53) had lymphatic invasion: 46% (22 of 48) of cases had extranodal extension. Of lymph node-positive cases, 61% had four or more metastatic lymph nodes. Of tumours with tumour size >10 mm, 77% had positive lymph nodes. The percentages of cases positive for oestrogen receptor (ER) and progesterone receptor (PR) were 68% and 61%, respectively. These values were significantly higher than the values for invasive ductal carcinomas. p53 and c-erbB-2 were detected in 48% and 54% of cases, respectively. The mean value of Ki67 was 26%. Follow-up was available in 36 patients. Eight patients had local recurrences, nine patients had distant metastases, and 10 patients died of disease within a follow-up period of 9 years. Lymphotropism and an unfavourable prognosis are the hallmarks of this distinct entity. Prognostic markers such as ER, PR, p53, and c-erbB-2 failed to provide new criteria to allow discrimination of these tumours from other breast cancers.Histopathology 02/2004; 44(1):18-23. DOI:10.1111/j.1365-2559.2004.01757.x · 3.30 Impact Factor